A PZEV version of the 177- and 190-horsepower four-cylinder engines is sold in California, Connecticut, Maine, Massachusetts, New York, Pennsylvania, Rhode Island and Vermont. The principal differences between the PZEV Accord and the ULEV-2 version sold in all states are single exhaust valve operation at low rpm, special dual-probe spark plugs and remapped Powertrain Control Module (PCM) programming, in addition to the near-zero evaporative emissions equipment. The horsepower, torque and EPA-estimated fuel economy of the PZEV and ULEV-2 engines are identical.
